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FNUS76 KSEW 201503
FWSSEW

Spot Forecast for ARCTIC JIM...NPS North Cascades
National Weather Service Seattle WA
803 AM PDT Mon Aug 20 2018

Forecast is based on forecast start time of 0800 PDT on August 20.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office at (206) 526-6095, if you have questions
or concerns with this forecast.

...RED FLAG WARNING IN EFFECT UNTIL 6 PM PDT THIS EVENING FOR
WIND AND LOW HUMIDITY...

.DISCUSSION...A Fraser Outflow pattern will bring strong northeast
wind across the Arctic Jim Fire today. Winds will be strongest
across the ridgetops but will mix into the valleys to a lesser
extent. The air mass will also be very dry today, with humidity
values well under 30 percent at times. Winds will ease quickly
tonight. On Tuesday, the air mass will remain dry, but wind speeds
will be significantly less.

.TODAY...

Sky/weather.........Sunny. Smoke.
CWR.................0 percent.
LAL.................1.
Max temperature.....Around 70.
Min humidity........23-27 percent.
Wind (20 ft)........
 Ridgetop...........North-Northeast winds 12 to 17 mph, with gusts
                    around 25 to 30 mph. Strongest mid-day and
                    early afternoon.
 Slope/valley.......East-northeast 6 to 12 mph.
Mixing height.......300-700 ft AGL increasing to 5500-6500 ft AGL
                    late this morning.
Transport winds.....Northeast around 15 mph.
Haines index........Mid-Level...5 or moderate.
Rainfall amount.....0.00 inches.

.TONIGHT...

Sky/weather.........Mostly clear. Smoke.
CWR.................0 percent.
LAL.................1.
Min temperature.....Around 51.
Max humidity........57 percent.
Wind (20 ft)........
 Ridgetop...........Northeast winds 5 to 12 mph in the evening,
                    easing to less than 5 mph overnight..
 Slope/valley.......Becoming downslope/downvalley 2 to 4 mph
                    around sunset.
Mixing height.......6500 ft AGL decreasing to 400-1400 ft AGL.
Transport winds.....Northeast around 11 mph.
Haines index........Mid-Level...5 or moderate.
Rainfall amount.....0.00 inches.

.TUESDAY...

Sky/weather.........Sunny. Smoke.
CWR.................0 percent.
LAL.................1.
Max temperature.....Around 75.
Min humidity........26 percent.
Wind (20 ft)........
 Ridgetop...........Northeast winds 3 to 7 mph.
 Slope/valley.......Upslope/upvalley 3 to 7 mph.
Mixing height.......300-600 ft AGL increasing to 4300-5300 ft AGL
                    after inversion breakout.
Transport winds.....East around 5 mph.
Haines index........Mid-Level...5 or moderate.
Rainfall amount.....0.00 inches.

$$
Forecaster...Haner
Requested by...LESHA ZITKOVICH
Type of request...WILDFIRE
.TAG 1814382.8/SEW
.DELDT 08/20/18
.EMAIL LESHA_ZITKOVICH@NPS.GOV